PP Plastic Hot Melt Gun

Product Model	Temperature-regulating hot air plastic welding gun
Category	PP-PPs Sheets
Reference Price	Price on request

Hot Customizable for Working Conditions 11 Technical Parameters

Product Overview

The PP plastic hot-melt welding gun is a handheld plastic welding tool that uses hot air as its heat source, mainly used for hot-melt joining of PP and PPs sheets and pipes. The heating core inside the gun heats the air drawn in by the fan, which is then ejected from the welding nozzle. The high-temperature hot air heats both the welding rod and the joint simultaneously, bringing the plastic to a molten state for pressure bonding, and a firm weld is formed after cooling.

The gun body features a heat-insulated structural design, and the handle conforms to handheld operation habits, reducing fatigue during extended use. The equipment temperature can be adjusted according to sheet thickness and ambient temperature. With different nozzles such as flat nozzles, round nozzles, triangular nozzles, and speed welding nozzles, it can perform various operations including seam welding, corner welding, root welding, cover welding, and speed welding, making it a common tool for anti-corrosion equipment fabrication in workshops and on-site engineering installation.

The plastic hot-melt welding gun supplied by Xicheng Environmental Protection is used together with PP flame-retardant welding rods and PPs sheets, suitable for spray tower shell rolling welding, duct longitudinal and circumferential seam welding, tank panel assembly, and on-site joint repair welding. The gun offers stable heating, fast heat-up, and high airflow; it can be used at fixed workstations in workshops or carried to elevated locations and confined spaces for on-site operations.

Working Principle

After the welding gun is connected to power, the motor drives the impeller to draw ambient air into the gun body. The air is rapidly heated as it flows through the ceramic or metal heating core, and the hot air is ejected directionally from the front nozzle. During welding, the nozzle is aimed at both the welding rod and the joint groove; the heat melts the rod surface and the sheet joint surface. The welder holds the rod and moves it along the joint at a constant speed while applying slight pressure. The molten plastic fills the joint and, after leaving the hot air zone, cools and solidifies to form the weld.

Temperature adjustment is key to ensuring welding quality. PP material can only fuse fully within the appropriate melting temperature range. Too low a temperature causes poor fusion between the rod and the base material, and the weld cracks under stress; too high a temperature causes the material to carbonize and yellow, produce pores, or even burn through thin sheets. Temperature-adjustable guns change heating power via a knob or electronic temperature control. Welders set the temperature according to sheet thickness, rod specifications, and ambient temperature, and control heat input through gun travel speed.

Structural Components

The welding gun mainly consists of a gun body shell, fan motor, heating core, temperature control assembly, welding nozzle, and power cord. The rear of the gun body houses the air inlet and fan, the middle section contains the insulated handle and heating chamber, and the front holds a replaceable welding nozzle. The temperature control knob or display is located above the handle for easy observation and adjustment during operation. The heating core is mostly designed to be replaceable and can be serviced individually after aging.

Welding nozzles come in various forms according to application. Flat nozzles eject wide hot air, suitable for sheet seam preheating and large-area welding; round nozzles concentrate heat and are used with round rods for root and corner welding; speed welding nozzles feature a rod guide groove through which the rod passes and is heated simultaneously, allowing one-handed rod feeding and welding, ideal for rapid welding of long straight seams.

Specifications and Models

The table below shows the power specifications and applicable scenarios of common plastic hot air welding guns. Please refer to the nameplate on the actual product for details.

Type	Applicable Scenarios	Welding Thickness
Low-power temperature-adjustable welding gun	Thin sheets, repair, on-site patch welding	2–8mm
Standard temperature-adjustable welding gun	Routine welding of ducts and tower shells	5–20mm
High-power welding gun	Thick sheets, multi-pass welding of tanks	Above 15mm
Speed welding kit	Continuous operation on long straight seams	Depending on nozzle configuration

Product Features

The PP plastic hot-melt welding gun features a compact structure and easy adjustment, making it a fundamental tool for plastic anti-corrosion equipment fabrication. Its main features are as follows.

Uniform hot air heating; the rod and base material melt simultaneously, delivering high weld strength
Continuously adjustable temperature, adaptable to sheets of different thicknesses and various working environments
Replaceable nozzles capable of seam welding, corner welding, and speed welding
Well-insulated body prevents hand burns during extended handheld operation
Fast heat-up; ready for welding shortly after startup
Compact and lightweight, convenient for elevated and confined on-site operations
Replaceable heating core, low maintenance cost, long service life

Material Welding	PP / PPs Plastic
Heating Method	Hot air heating
Temperature Regulation	Adjustable Temperature
Welding Nozzle Type	Flat nozzle / round nozzle / quick-change welding nozzle
Power Supply Method	AC Power Supply
Cooling Method	`Cooling Fan`
Handheld Design The product features a compact and ergonomic handheld design, optimized for ease of	Handheld
Companion Welding Electrodes	PP Round Welding Electrode / Triangular Welding Electrode
Applicable plate thickness	2–20mm and above
Equipment Form	Handheld hot air welder
Applicable Scenarios	On-site welding and workshop welding

Application Industries

Shop welding of spray towers and tanks in anticorrosion equipment manufacturing plants
Longitudinal and circumferential welding of PPs ventilation ducts on installation sites
Manufacturing and rewelding of electroplating acid washing tanks and chemical water tanks
Repair welding of pipe joints during maintenance of exhaust gas treatment projects
Processing and fabrication of laboratory fume hoods and plastic exhaust hoods
On-site pipe modification and welding for acid-base exhaust systems in semiconductor factories
Field operations for outdoor and high-altitude work by environmental equipment installation companies

Typical Process Locations

The hot melt welding gun covers the entire process from manufacturing to installation of PPs equipment. In the workshop, the gun works with fixtures to complete the curling of longitudinal seams, circumferential seams of cylindrical bodies, corner seams of flanges, and internal reinforcement structure welding after plate cutting. On the construction site, the gun is used for butt welding between prefabricated pipe sections, connecting equipment inlets/outlets with ventilation ducts, and local sealing near support brackets.

During maintenance and repair, the gun is the primary tool for handling leaks and Renovation openings. When weld leaks occur during equipment operation, the medium is drained, the surface is cleaned, and the gun is used with electrodes for rewelding. When production line adjustments require adding branch pipes or connections, openings are made on-site, and the gun is used to weld short pipes and flanges. The portability of the gun allows these operations to be completed without returning the equipment to the factory. Before use, the hot air temperature is adjusted based on plate thickness and ambient temperature. A test weld is performed on scrap material to confirm good fusion before starting the actual welding. During welding, the gun, electrodes, and weld seams maintain a stable angle and uniform speed. After the job is finished, the gun nozzle is cleaned promptly, cooled, and stored. Power cords and heating cores are inspected regularly. Field operations should be kept away from flammable materials and ensure proper ventilation.

Principles are similar, but direct interchangeability is not recommended. Plastic welding guns are designed for plastic hot melt welding, featuring stable temperature control, concentrated airflow, and a dedicated welding rod guide nozzle that heats both the welding rod and the joint simultaneously. Standard hot air guns are primarily used for film application, baking, and heat shrinking, with significant temperature fluctuations, dispersed airflow, and no specialized nozzles. This makes them prone to overheating, burning through, or uneven heating, resulting in unreliable weld strength. For load-bearing and sealing welds, specialized plastic welding guns with matching nozzles must be used to control penetration depth and shaping. Standard hot air guns can be used for auxiliary heating in non-load-bearing areas but cannot replace welding guns. With extensive experience in plastic equipment manufacturing and installation, equipping with a temperature-stable, specialized welding gun is more reliable.

Poor electrode adhesion is usually caused by cold soldering, common reasons include low temperature, gun movement too fast, seams not cleaned properly, or insufficient electrode pressure. First confirm the gun temperature reaches PP melting requirements, remove oxidation and contaminants from the seam surface with a scraper before welding, ensure the electrode and base material show a molten glow simultaneously during welding, keep the electrode perpendicular to the weld and apply stable pressure. Test weld with scrap material before actual welding, after cooling, forcefully peel the weld to check, a well-fused weld should not tear along the joint surface.

Most temperature-regulating plastic welding guns feature a replaceable heating core. To replace it, first power off and allow the gun body to cool completely. Then, remove the outer casing screws, disconnect the wiring terminals of the old heating core, install the new one, and restore it as before. When replacing, use a heating core of the same model and power specification. Ensure the wiring terminals are securely connected, the heat insulation and sealing components are properly reset, to prevent air leakage or excessive heat buildup on the casing. After assembly, perform an empty-load test run to check if heating, temperature regulation, and airflow are normal before putting it into welding. If the fan motor and temperature control circuit are both damaged, or the gun casing is aging, deformed, or exhibits reduced insulation, it is recommended to replace the entire unit to avoid temperature control failure after repair, which could lead to overheating and fire hazards. When in doubt, it is safer to leave the repair to professionals.

Yellowing and blackening of the plate indicate over-heat carbonization, suggesting the welding torch temperature setting is too high, or the welding tip remains stationary at the same position for too long, or the welding speed is too slow. Overheating of polypropylene leads to decomposition and carbonization. The carbonized areas become brittle, strength decreases, and the weld develops porosity, which cannot be salvaged through re-welding. It is necessary to completely remove the carbonized layer and re-weld. The temperature setting should be reduced, and the welding tip and electrode should move uniformly along the weld to ensure even heat input, avoiding prolonged heating at localized points. For thick plate welding, multi-layer multi-pass welding is recommended, controlling inter-pass temperature rather than single high-temperature, long-duration baking. Preheating can be applied when the ambient temperature is low or the plate is thick, but the preheating temperature must also be uniform, avoiding localized baking.

The welding site should be well-ventilated to promptly expel the small amount of smoke generated by the heat from the plastic heating. Operators should avoid facing the nozzle's outlet directly and wear protective goggles and heat-resistant gloves when necessary. When in use, the front end of the gun body and the nozzle are very hot and should not be touched by skin or flammable materials. When work is paused, it should be placed on a dedicated stand and should not be placed directly on plates, scaffolding, or flammable materials. After work is completed, power must be turned off, and the gun must be stored only after it has naturally cooled. It is strictly forbidden to place the gun in a box while it is still hot. During confined space and high-altitude operations, power cords must be intact and free of damage and kept away from high-temperature areas. Flammable materials should be cleared below, fire extinguishing equipment should be provided, and measures to prevent burns and fire should be taken. The exterior of the welding machine should be kept dry. During outdoor operations in rainy weather, measures to prevent rain and electrical leakage should be implemented.

The quick welding tip features a welding electrode guide channel, where the electrode is preheated by hot air as it passes through the tip. The welder can control both the gun and the electrode with one hand, enabling fast travel speeds and uniform, consistent weld bead formation. It is ideal for long straight welds and batch construction, significantly improving efficiency and reducing reliance on technique. The standard round tip requires a second hand to feed the electrode, with adjustable angles and speeds for high flexibility, making it suitable for complex areas like elbows, pipe bends, and flange corner seams, as well as tight spaces. When used with proper temperature and technique, both tips offer comparable welding strength; the main difference lies in construction efficiency and application areas. In engineering practice, the quick tip is typically used for long straight sections, while the round tip handles edges, corners, and irregular areas. The two are often used in combination. When equipped with a gun, each type of tip comes with a set, and the corresponding specifications should be selected based on the electrode diameter.

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